Lee Sin Lv1-2 is the best time to get a kill
use your Q and then use your auto attack and let the enemy think u get less hp then him look at ur passive if it is almost finish use the following Q

At Lv2 use your Q to get close your enemy and use your E for chasing him and wait your Q for cool down

Lv4 You can now use your W to the get to the minions which is close to your enemy then E and Q

LV6 You can get a Combo like Q then use your Ult and use Your Q to get a pound of damage

Farm up yourself and get Warmog as fast as u can

Use your W and shield your carry use your E the slow your enemy and make their attack speed slow
and kill them one by one Warmog will give u enough Hp to survive in Team Fight

*You can use your Lantern for warding over wall and use your W to get away if needed

If you are interest You can find EnDT in Game Us Server for some more information or Try a 1v1:D